matrix-dice/index.js

function Dice(matrixClient) {
	this.matrixClient = matrixClient;
	this.blacklistedRooms = [];
}

function getRandomInt(min, max) {
  max = Number(max) + 1
  min = Math.ceil(min);
  max = Math.floor(max);
  return Math.floor(Math.random() * (max - min)) + min; //The maximum and the minimum are inclusive
}

Dice.prototype.setBlacklistedRooms = function(blacklistedRooms) {this.blacklistedRooms = blacklistedRooms;};

Dice.prototype.handleMessage = function(event, room) {

	if (this.blacklistedRooms.indexOf(room.roomId) >=0) {
		return;
	}

	var messagePieces = event.getContent().body.split(" ");

        if (messagePieces[0] === "!roll") {

                // These default min and max values are so !roll give us a "chan-like" result
                var min = 100000000;
                var max = 1000000000;
                var numOfTimes = 1;

                switch (messagePieces.length) {
                case 4:
                        numOfTimes = messagePieces[3]
                case 3:
                        min = messagePieces[1];
                        max = messagePieces[2];
                        break;
                case 2:
                        min = 1;
                        max = messagePieces[1];
                        if (/^\d+d\d+$/.test(messagePieces[1])) {
                                var dsplit = messagePieces[1].split("d");
                                numOfTimes = dsplit[0];
                                max = dsplit[1];
                        }
                case 1:
                        break;
                default:
                        this.matrixClient.sendNotice(room.roomId, "Invalid roll parameters.");
                        return;
                }

                this.roll(min, max, numOfTimes, event, room);

        }
}

Dice.prototype.roll = function roll(min, max, numOfTimes, event, room) {

        if (isNaN(min) || isNaN(max) || isNaN(numOfTimes)) {
                this.matrixClient.sendNotice(room.roomId, "Invalid roll parameters.");
                return;
        }
        else if (numOfTimes > 10 || numOfTimes < 1) {
                this.matrixClient.sendNotice(room.roomId, "Minimum of 1 roll, maximum of 10 rolls.");
                return;
        }

        var results = new Array(numOfTimes);
        var formattedBody = "<a href=\"https://matrix.to/#/"+event.getSender() + "\">"+event.getSender()+"</a>: Your rolls are:";;
        var body = event.getSender()+ ": Your rolls are:"

        if (numOfTimes == 1) {
                var result = getRandomInt(min,max);
                formattedBody = "<a href=\"https://matrix.to/#/"+event.getSender() + "\">"+event.getSender()+"</a>: Your roll is: "+result;
                body = event.getSender()+ ": Your roll is: "+result;
        }
        else {
                for(var i = 0; i < numOfTimes; i++) {
                        results[i] = getRandomInt(min,max);
                        formattedBody += "<br />Roll "+(i+1)+": "+results[i];
                        body += "\r\nRoll "+(i+1)+": "+results[i];
                }
        }

        var content = {
            "format": "org.matrix.custom.html",
            "body": body,
            "formatted_body": formattedBody,
            "msgtype": "m.text"
        };
        this.matrixClient.sendEvent(room.roomId, "m.room.message", content, "", (err, res) => {
            	if (err != null) {
			console.error(err);
		}
        });

}

Dice.prototype.getFormattedHelp = function() {
        return "<code>!roll</code> - Roll a number from 100000000 to 1000000000<br />\
	       <code>!roll [number of rolls]d[max]</code> - Roll a number from 1 to [max] the number of times specified (10 max). Example: <code>!roll 3d20</code><br />\
	       <code>!roll [max]</code> - Roll a number from 1 to [max] (example: <code>!roll 100</code>)<br />\
	       <code>!roll [min] [max]</code> - Roll a number from [min] to [max] (example: <code>!roll 25 100</code>)<br />\
	       <code>!roll [min] [max] [number of rolls]</code> - Roll a number from [min] to [max] the [number of rolls] specified (10 max) (example: <code>!roll 25 100 5</code>)"
}

Dice.prototype.getHelp = function() {
        return   "!roll\" - Roll a number from 100000000 to 1000000000\r\n\
	        \"!roll [number of rolls]d[max]\" - Roll a number from 1 to [max] the number of times specified (10 max). Example: \"!roll 3d20\"\r\n\
	        \"!roll [max]\" - Roll a number from 1 to [max] (example: \"!roll 100\")\r\n\
	        \"!roll [min] [max]\" - Roll a number from [min] to [max] (example: \"!roll 25 100\")\r\n\
	        \"!roll [min] [max] [number of rolls]\" - Roll a number from [min] to [max] the [number of rolls] specified (10 max) (example: \"!roll 25 100 5\")"
}

module.exports = Dice;